Corrupt PCBs can't be smoothly recovered from

[JarrettR]

If something bad happens and Stretch generates a corrupt/invalid PCB, and then you won't be able to open it in KiCad. When you can't open it, you can't click the DOWN arrow, and can't generate a new, good PCB.

Current workaround is just to replace the PCB file with literally any one that works in your OS file manager so you can open it and hit that arrow, but it's janky.

A slightly better solution is to back up the existing PCB before replacing it with the newly generated one.